What will Charles Clarke's new proposed provisions allow the government to do?

The home secretary will be able to impose control orders on anyone, whether British or foreign, without charge if there are reasonable grounds to suspect that person of involvement in terrorism, domestic or international. Under current law, restrictions on a suspect's movements can be imposed when granting bail, but only by the courts and only if the suspect has been charged. The orders will impose one or more of a range of restrictions including curfews, electronic tagging, a ban on the use of telephones or the internet, restrictions on those the subject may associate with, and house arrest.

Why are the measures being extended to domestic terror subjects as well as foreign ones?

The Anti-Terrorism, Crime and Security Act 2001 allowed foreign terror suspects to be held indefinitely without charge or trial. The law required Britain to opt-out of article 5 of the European convention on human rights.

Last month the law lords ruled that the opt-out breached the convention because detention without trial of foreign, but not British suspects, was discriminatory and disproportionate to the threat from terrorism.

Will people who are subjected to the orders know what evidence is held against them?

Like the foreign detainees currently held, they will have no right to know the secret intelligence evidence against them.

Is house arrest legally different from incarceration?

For the purposes of the European convention on human rights, what counts is whether the individual has been deprived of the right to liberty. Most lawyers say house arrest deprives a person of liberty.

Will people be able to appeal against the new orders?

The plan is that they will be able to have the orders reviewed periodically by a security-cleared judge, as the foreign detainees now do by the Special Immigration Appeals Commission. There will probably be a system of special advocates appointed by the government, with security clearance to represent those subjected to the orders. They would be able to see the secret evidence but would not be able to discuss it with the suspects.

Has any British government taken such measures before?

In 1940 the home secretary made orders for the detention of 1,428 people, including British citizens, some in internment camps. There was also internment without trial in Northern Ireland.

How does the government justify the suspension of such basic civil rights?

It says its needs the powers to prevent terrorist acts.

Why will the government not introduce a law creating an offence for which terror suspects could be prosecuted?

The suggestion of a new offence of doing acts preparatory to terrorism is being looked at as part of a wider review of terrorism law. Such an offence could allow more terror suspects to be prosecuted.

Why will the government not reveal the evidence it has against the Belmarsh detainees and other terror suspects?

It says that in some cases does not want to reveal evidence in court because it might compromise sources or because it is weak, or even obtained by torture from informants abroad. The intelligence agencies say they do not want to alert potential terrorists to their methods.

Why will the government not agree to the use of wiretap evidence in trials?

The risks, it says, outweigh the advantages. They include alerting defendants, or others to individual telephone numbers which have been tapped. Anti-terrorist officials say the significance of phone tap evidence has been exaggerated. The main source of evidence, they say, is human intelligence.

Why are opposition parties not more critical of Charles Clarke's proposed measures?

The response has been muted because they are still hopeful that they can achieve some kind of cross-party agreement with a new conciliatory home secretary. The lower key approach also reflects the impending general election campaign with all parties conscious that they could pay a heavy political price for outright opposition to the second reading of the bill implementing the new measures.